Spermophilus

Spermophilus is the most diverse and rich genus of ground squirrels. In 1825, the naming of the genus Spermophilus was given by Georges Cuvier, a French naturalist, and zoologist. They are widely distributed in Europe, Asia, and North America. Spermophilus comprises a variety of habitats, including tropical, subtropical, and temperate forests; hot and cold deserts; prairies and steppes; grasslands and meadows. Being a social animals, habitually, they live in communities and are most visible during the daytime. They construct a hole or tunnel excavated into the ground, called caves, and use that for nesting, refuging, hiding, and hibernation. These caves are typically unmarked by small hillocks of excavated dirt, making them very difficult to discover.

Apart from geographic allocations and habitat diversity, Spermophilus can be differentiated by morphological characteristics such as body size, skull conformation, limb and tail structure or quantities, and mammary number. Phenotypically they have different body colorations, e.g., yellowish, light orangish, brownish, or greyish. Most of the species are mottled or spotted or have orange pigmentations on the head. Although the size of the species varies, usually, they have 17–40 cm of head-and-body length. They also have a short tail size of 10–45% of the head-and-body length.

Reproduction of Spermophilus occurs only once a year, in late March or early April. Their diet includes green vegetables, meat, and insects, although it varies depending on spring and summer. Occasionally they climb into low bushes to forage, but most of their food is gathered on the ground. Sporadically, they can create tunneling underneath human residences and may also spread diseases to humans by carrying fleas.

Historically, chromosomal studies were used to determine the taxonomic relationship among ground squirrels; however, nowadays, bio-molecular studies have been used to elucidate phylogenetic relationships among ground squirrel species, including Spermophilus. For example, a phylogenetic analysis was undertaken in 2009 using the mitochondrial gene cytochrome b, which split the genus Spermophilus into eight genera. [Zimam Mahmud]